Vehicle air conditioning apparatus

ABSTRACT

A vehicle air conditioning apparatus is provided. The vehicle air conditioning apparatus includes: a plurality of seat air conditioning units configured to selectively perform cooling or heating for corresponding seats installed in a cabin, respectively; and a plurality of exhaust ducts for discharging, outside the cabin, part of air used in the plurality of seat air conditioning units. At least part of the plurality of exhaust ducts is merged.

TECHNICAL FIELD

The present invention relates to a vehicle air conditioning apparatus.

BACKGROUND ART

Conventionally, as an on-vehicle air conditioning apparatus is provideda system in which cooled or heated air-conditioned air is supplied tothe surrounding of a seated occupant (see, for instance, JP2006-35952Aand JP2016-145015A). Such a vehicle air conditioning apparatus can coolor heat the surrounding of an occupant in a locally concentrated manner.This makes it possible to provide a comfortable space to the occupanteven immediately after initiation of cooling or heating operation, etc.

SUMMARY OF INVENTION Technical Problem

An in-seat heat exchanger of the vehicle air conditioning apparatusdescribed in JP2006-35952A has a simple structure such that heat isexhausted outside a vehicle while a heat source/cold source, which isassumed to be a Peltier element, is switched. This vehicle airconditioning apparatus described in JP2006-35952A has problems of poorefficiency and easy-to-occur performance/power deficiency when thePeltier element is used for cooling and/or heating treatment of airsupplied.

Meanwhile, the seat air conditioning unit described in JP2016-145015Ahas a vapor compression heat exchanger installed in a seat. The problemof this seat air conditioning unit described in JP2016-145015A is thatheated air during cooling and cooled air during heating cannot beexhausted outside a vehicle. In addition, the seat air conditioning unitdescribed in JP2016-145015A needs a blower fan per exchanger.Unfortunately, this causes the size of the air conditioning unit to beenlarged, which is likely to make the structure complex and increasecost.

The present invention provides a solution to the above problems. Themain purpose of the present invention is to provide a highly efficientvehicle air conditioning apparatus such that the internal structure ofseat is simplified and heat from a vapor compression heat exchanger canbe exhausted outside a vehicle.

Solution to Problem

An aspect of the present invention provides a vehicle air conditioningapparatus includes: a plurality of seat air conditioning unitsconfigured to selectively perform cooling or heating for correspondingseats installed in a cabin, respectively; and a plurality of exhaustducts for discharging, outside the cabin, part of air used in theplurality of seat air conditioning units. At least part of the pluralityof exhaust ducts is merged.

The vehicle air conditioning apparatus according to the presentinvention can reduce the number of blowing fans and thus simplify an airconditioning apparatus.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A is a schematic diagram of the structure of a vehicle airconditioning apparatus according to an embodiment when viewed from alateral side.

FIG. 1B is a schematic diagram of the structure of a seat airconditioning unit of the vehicle air conditioning apparatus according tothe embodiment when viewed from a lateral side.

FIG. 2 is a schematic diagram of the structure of the vehicle airconditioning apparatus according to the embodiment when viewed from theabove.

FIG. 3 is a diagram illustrating how the vehicle air conditioningapparatus works during cooling operation.

FIG. 4 is a diagram illustrating how the vehicle air conditioningapparatus works during heating operation.

FIG. 5A is a schematic diagram of the structure of a front airconditioning unit when viewed from the above.

FIG. 5B is a schematic diagram of the structure of the seat airconditioning unit when viewed from the above.

FIG. 5C is a schematic diagram of the structure of a rear blowing unitwhen viewed from the above.

FIG. 6 is a diagram illustrating how the front air conditioning unitworks during cooling operation.

FIG. 7A is a diagram illustrating how the front air conditioning unitworks when the temperature of a cabin front section is raised duringheating operation.

FIG. 7B is a diagram illustrating how the front air conditioning unitworks when the outside air temperature is high (at about 0° C.) duringheating operation.

FIG. 7C is a diagram illustrating how the front air conditioning unitworks when the outside air temperature is low during heating operation(when each seat air conditioning unit is deficient in performance).

FIG. 8 is a diagram illustrating how the seat air conditioning unitworks during cooling operation.

FIG. 9 is a diagram illustrating how the seat air conditioning unitworks during heating operation.

FIG. 10 is a schematic diagram of the structure of a seat airconditioning unit of an air conditioning apparatus according to acomparative embodiment when viewed from a lateral side.

FIG. 11 is a diagram illustrating how the seat air conditioning unitaccording to the comparative embodiment works during cooling operation.

FIG. 12 is a diagram illustrating how the seat air conditioning unitaccording to the comparative embodiment works during heating operation.

DESCRIPTION OF EMBODIMENTS

Hereinafter, an embodiment of the present invention (hereinafter,referred to as the present embodiment) is described in detail withreference to the Drawings. Note that each figure just schematicallydepicts the present invention in a sufficiently understandable manner.Thus, the present invention is not limited to each embodiment depicted.Also, in each figure, the same elements or similar elements have thesame reference numerals so as to avoid redundancy.

Embodiment

This embodiment provides an air conditioning apparatus 10 in which thenumber of blowing fans is reduced. In addition, this embodiment providesthe air conditioning apparatus 10 so as to provide a solution to theproblems of a seat air conditioning unit (see FIGS. 10 to 12) of an airconditioning apparatus according to the below-described comparativeembodiment.

<Structure of Whole Air Conditioning System>

With reference to FIGS. 1A to 4, the following describes the structureof the whole air conditioning apparatus 10 according to this embodiment.The air conditioning apparatus 10 is an on-vehicle air conditioningapparatus. FIG. 1A is a schematic diagram of the structure of the airconditioning apparatus 10 when viewed from a lateral side. FIG. 1B is aschematic diagram of the structure of a seat air conditioning unit 30 ofthe air conditioning apparatus 10 when viewed from a lateral side. FIG.2 is a schematic diagram of the structure of the air conditioningapparatus 10 when viewed from the above. FIG. 3 is a diagramillustrating how the air conditioning apparatus 10 works during coolingoperation. FIG. 4 is a diagram illustrating how the air conditioningapparatus 10 works during heating operation.

As shown in FIG. 1A, the air conditioning apparatus 10 includes one ormore front air conditioning units 20, a plurality of seat airconditioning units 30, and one or more rear blowing units 40. Here,assumed and described is a case where the number of the front airconditioning units 20 is 1, the number of the seat air conditioningunits 30 is 4, and the number of the rear blowing units 40 is 2 (seeFIG. 2).

The front air conditioning unit 20 is a unit for supplying outside air(air outside a cabin) to each seat air conditioning unit 30. The frontair conditioning unit 20 is installed at a front section 102 of avehicle 100. In this embodiment, the front air conditioning unit 20functions to heat outside air (air outside a cabin) and inside air (airinside the cabin). Note that the front air conditioning unit 20 may beconfigured to have a function of cooling outside air and inside air.

Each seat air conditioning unit 30 is a unit for selectively performingcooling or heating per corresponding seat 104. Each seat airconditioning unit 30 is installed at each seat 104 arranged in a cabin103 (see FIG. 2). The inside of each seat air conditioning unit 30contains a refrigerant for exchanging heat with the air.

Note that the seat air conditioning unit 30 may be a refrigerating cycleapparatus which includes a compressor, an evaporator, a condenser, andan expansion valve and through which a refrigerant circulates. In thiscase, during cooling operation, the evaporator generates cold air forcooling and, at the same time, the condenser generates heat. Because ofthis, this heat generated by the condenser is discharged, as waste heat,outside the vehicle so as to increase cooling efficiency. In addition,during heating operation, the condenser of each seat air conditioningunit 30 generates warm air for heating and, at the same time, theevaporator generates cold heat. Because of this, this cold heatgenerated by the evaporator is discharged, as waste heat, outside thevehicle so as to increase heating efficiency.

This point applies to cooling/heating operation conducted, without arefrigerant, by using a Peltier element. During cooling operation,simultaneously generated heat is drained outside the vehicle; and duringheating operation, simultaneously generated cold heat is drained outsidethe vehicle.

Each rear blowing unit 40 is a unit for discharging, to the outsidethrough a vent hole 50 b (see FIG. 2), heat and part of air (outsideair) used in the front air conditioning unit 20 and each seat airconditioning unit 30. Each rear blowing unit 40 is installed at a rearsection of the vehicle 100.

As shown in FIG. 1B, each seat air conditioning unit 30 of the airconditioning apparatus 10 is structured such that during cooling/heatingoperation, cooled or heated air-conditioned air, for example, issupplied to the surrounding of an occupant seated on the seat 104. Suchan air conditioning apparatus 10 can supply air-conditioned air to thesurrounding of an occupant. This makes it possible to provide acomfortable space to the occupant immediately after initiation ofcooling or heating operation, etc.

As shown in FIG. 2, this embodiment provides the air conditioningapparatus 10 including one front air conditioning unit 20, four seat airconditioning units 30, two rear blowing units 40, and ducts 60 throughwhich air flows between the respective units.

FIG. 2 illustrates an example where the vehicle 100 includes one frontair conditioning unit 20 at the front section 102. In addition, thevehicle 100 includes the total of four seats 104 on the front rightside, the front left side, the rear right side, and the rear left side.Meanwhile, each seat 104 is provided with one seat air conditioning unit30. In addition, the vehicle 100 includes the total of two rear blowingunits 40, each on the rear right side or the rear left side.

The ducts 60 include: air supply ducts 61 connecting the front airconditioning unit 20 and each seat air conditioning unit 30; exhaustducts 62 connecting each seat air conditioning unit 30 and acorresponding rear blowing unit 40; and ventilation ducts 63 connectingeach rear blowing unit 40 and a corresponding vent hole 50 b.

Each air supply duct 61 is a duct for supplying, to a corresponding seatair conditioning unit 30, outside air so as to drain heat. The airsupply duct 61 may be arranged, for instance, below a vehicle bodyfloor, inside a center tunnel, and/or inside a center console.

Each exhaust duct 62 or each ventilation duct 63 is a duct fordischarging, outside the cabin (outside the cabin 103), part of air(outside air) used in each seat air conditioning unit 30. Theventilation duct 63 is disposed downstream of a corresponding exhaustduct 62. Each exhaust duct 62 and the corresponding ventilation duct 63are used to discharge, outside the cabin, the outside air with warm heatgenerated by each seat air conditioning unit 30 during cooling operationor cold heat generated by each seat air conditioning unit 30 duringheating operation.

Also, in this embodiment, each seat air conditioning unit 30 is providedwith: a first route (see the arrows A11) through which inside aircirculates; and a second route (see the arrows A21, A22, A23, and A24)through which outside air flows. The first route and the second routeare separated to give independent structures.

Each seat air conditioning unit 30 is likewise structured. Hereinafter,when each seat air conditioning unit 30 is distinguished, the unit onthe front right side, the front left side, the rear right side, or therear left side is denoted by adding alphabet characters “FR”, “FL”,“RR”, or “RL”, respectively, to the end of reference numeral of eachseat air conditioning unit 30. Specifically, each unit is referred to asa “seat air conditioning unit 30FR”, “seat air conditioning unit 30FL”,“seat air conditioning unit 30RR”, or “seat air conditioning unit 30RL”.

In addition, when each air supply duct 61 connected to the correspondingseat air conditioning unit 30 is distinguished, the duct on the frontright side, the front left side, the rear right side, or the rear leftside is denoted by adding alphabet characters “FR”, “FL”, “RR”, or “RL”,respectively, to the end of reference numeral of each air supply duct61. Specifically, each duct is referred to as an “air supply duct 61FR”,“air supply duct 61FL”, “air supply duct 61RR”, or “air supply duct61RL”.

Further, when each exhaust duct 62 connected to the corresponding seatair conditioning unit 30 is distinguished, the duct on the front rightside, the front left side, the rear right side, or the rear left side isdenoted by adding alphabet characters “FR”, “FL”, “RR”, or “RL”,respectively, to the end of reference numeral of each exhaust duct 62.Specifically, each duct is referred to as an “exhaust duct 62FR”,“exhaust duct 62FL”, “exhaust duct 62RR”, or “exhaust duct 62RL”.

Furthermore, when the ventilation duct 63 on the right side isdistinguished from the ventilation duct 63 on the left side, theventilation duct 63 on the right side is referred to as a “ventilationduct 63R”; and the ventilation duct 63 on the left side is referred toas an “ventilation duct 63L”.

The front air conditioning unit 20 is connected via four air supplyducts 61 to four seat air conditioning units 30. Part of the four airsupply ducts 61 is merged. For instance, FIG. 2 shows an example of ashape where the four air supply ducts 61 are connected to a linear pipearranged at substantially the middle. In other words, the four airsupply ducts 61 are shaped such that a linear pipe arranged atsubstantially the middle branches into four directions toward the fourcorresponding seat air conditioning units 30. The air outlet side(terminal end side) of each air supply duct 61 is connected to an airinlet for incorporating outside air into each seat air conditioning unit30.

The seat air conditioning unit 30FR on the front right side is connectedvia the exhaust duct 62FR to the rear blowing unit 40R on the rightside. In addition, the seat air conditioning unit 30RR on the rear rightside is connected via the exhaust duct 62RR to the rear blowing unit 40Ron the right side. The exhaust duct 62FR and the exhaust duct 62RR aremerged partway into one and connected to the rear blowing unit 40R onthe right side.

The rear blowing unit 40R on the right side is connected via theventilation duct 63R to a vent hole 50 bR. The vent hole 50 bR is opento the outside of the cabin.

The seat air conditioning unit 30FL on the front left side is connectedvia the exhaust duct 62FL to the rear blowing unit 40L on the left side.In addition, the seat air conditioning unit 30RL on the rear left sideis connected via the exhaust duct 62RL to the rear blowing unit 40L onthe left side. The exhaust duct 62FL and the exhaust duct 62RL aremerged partway into one and connected to the rear blowing unit 40L onthe left side.

The rear blowing unit 40L on the left side is connected via theventilation duct 63L to a vent hole 50 bL. The vent hole 50 bL is opento the outside of the cabin.

Outside air is taken via an introduction port 50 a into the front airconditioning unit 20 and is supplied from the front air conditioningunit 20 via each air supply duct 61 to each seat air conditioning unit30 (see the arrows A21 and A22). The outside air supplied to each seatair conditioning unit 30 is sent from each seat air conditioning unit 30via each exhaust duct 62 to the corresponding rear blowing unit 40 (seethe arrows A23). At that time, when the operation state is duringcooling operation, the outside air is heated by each seat airconditioning unit 30 (that is, waste warm heat is absorbed). Bycontrast, when the operation state is during heating operation, theoutside air is cooled by each seat air conditioning unit 30 (that is,waste cold heat is absorbed). Then, the outside air sent to each rearblowing unit 40 is sent from the rear blowing unit 40 via thecorresponding ventilation duct 63 to the corresponding vent hole 50 b soas to be discharged from the vent hole 50 b to the outside of the cabin.At that time, the outside air is pressurized by each rear blowing unit40 and is then delivered to the downstream side.

In contrast to such outside air, inside air is incorporated from theinside of the cabin into each seat air conditioning unit 30. After heatis exchanged, as needed, depending on the operation state, the insideair is discharged to the inside of the cabin (see the arrows A11).

<How Air Conditioning System Works During Cooling Operation>

With reference to FIG. 3, the following illustrates how the airconditioning apparatus 10 works during cooling operation. FIG. 3 is adiagram illustrating how the air conditioning apparatus 10 works duringcooling operation. Note that, the front air conditioning unit 20 has abuilt-in heater 27 configured to selectively heat inside air or outsideair. In addition, each seat air conditioning unit 30 has a heatexchanger 37 including a condenser 37 a and an evaporator 37 b.

As shown in FIG. 3, during cooling operation, the heater 27 of the frontair conditioning unit 20 is in an OFF state. In addition, the front airconditioning unit 20 is in a state in which inside air circulation isstopped (that is, in a state in which incorporation of inside air fromthe cabin and discharge of the inside air into the cabin are stopped).Also, in the heat exchanger 37 of each seat air conditioning unit 30,the condenser 37 a and the evaporator 37 b are in an ON state.

The front air conditioning unit 20 incorporates outside air from theintroduction port 50 a thereinto and supplies the outside air via eachair supply duct 61 to each seat air conditioning unit 30. Each seat airconditioning unit 30 takes in inside air from the cabin (see the arrowsA11) and heat is then exchanged by the heat exchanger 37 between arefrigerant and the inside air and between a refrigerant and the outsideair. At that time, in each seat air conditioning unit 30, the outsideair is heated by the condenser 37 a (that is, waste warm heat is givento the outside air) and the inside air is cooled by the evaporator 37 b.

Each seat air conditioning unit 30 sends the outside air heated by thecondenser 37 a, via each exhaust duct 62, to the corresponding rearblowing unit 40. The rear blowing unit 40 sends the outside air via thecorresponding ventilation duct 63 to the corresponding vent hole 50 band the outside air is then discharged from the vent hole 50 b to theoutside of the cabin. In this way, the air conditioning apparatus 10 candischarge the outside air with heat to the outside of the cabin. Thatis, the air conditioning apparatus 10 discards, as waste heat, warm heatgenerated by the condenser 37 a of each seat air conditioning unit 30.In addition, the air conditioning apparatus 10 can release, into thecabin, the inside air cooled by the evaporator 37 b. This enablescooling of the cabin 103 to be conducted by the air conditioningapparatus 10.

<How Air Conditioning System Works During Heating Operation>

With reference to FIG. 4, the following illustrates how the airconditioning apparatus 10 works during heating operation. FIG. 4 is adiagram illustrating how the air conditioning apparatus 10 works duringheating operation.

As shown in FIG. 4, during heating operation, the heater 27 of the frontair conditioning unit 20 is in an ON state. In addition, the front airconditioning unit 20 is in a state in which inside air circulation isimplemented (that is, in a state in which incorporation of inside airfrom the cabin and discharge of the inside air into the cabin areimplemented). Also, in the heat exchanger 37 of each seat airconditioning unit 30, the condenser 37 a and the evaporator 37 b are inan ON state. Note that when each seat air conditioning unit 30 cangenerate adequately warm heat, the heater 27 of the front airconditioning unit 20 may be turned OFF.

In the front air conditioning unit 20, inside air is taken in from thecabin, the inside air is heated by the heater 27, and the heated insideair is then released into the cabin (see the arrow A10). In addition,the front air conditioning unit 20 incorporates outside air from theintroduction port 50 a thereinto and supplies the outside air via eachair supply duct 61 to each seat air conditioning unit 30. Each seat airconditioning unit 30 takes in inside air from the cabin (see the arrowsA11) and heat is then exchanged by the heat exchanger 37 between arefrigerant and the inside air and between a refrigerant and the outsideair. At that time, in each seat air conditioning unit 30, the outsideair is cooled by the evaporator 37 b (that is, waste cold heat is givento the outside air) and the inside air is heated by the condenser 37 a.

Each seat air conditioning unit 30 sends the outside air cooled by theevaporator 37 b, via each exhaust duct 62, to the corresponding rearblowing unit 40. The rear blowing unit 40 sends the outside air via thecorresponding ventilation duct 63 to the corresponding vent hole 50 band the outside air is then discharged from the vent hole 50 b to theoutside of the cabin. In this way, the air conditioning apparatus 10 candischarge the resulting outside air to the outside of the cabin. Thatis, the air conditioning apparatus 10 discards, as waste heat, cold heatgenerated by the evaporator 37 b of each seat air conditioning unit 30.In addition, the air conditioning apparatus 10 can release, into thecabin, the inside air heated by the condenser 37 a. This enables heatingof the cabin 103 to be conducted by the air conditioning apparatus 10.

<Configuration of Front Air Conditioning Unit>

With reference to FIG. 5A, the following describes the structure of thefront air conditioning unit 20. FIG. 5A is a schematic diagram of thestructure of the front air conditioning unit 20 when viewed from theabove.

As shown in FIG. 5A, the front air conditioning unit 20 includes: aninside/outside air switching damper 21 for switching an inside air flowand an outside air flow; a filter 25 for removing fine dust contained inthe inside air; fans 26 for causing the inside air and/or the outsideair to flow; and a heater 27 for selectively heating the inside airand/or the outside air. The inside/outside air switching damper 21 isprovided with: two inside air-flowing passages (the first inside airpassage 21 a 1 and the second inside air passage 21 a 2); and oneoutside air-flowing passage (outside air passage 21 b). The front airconditioning unit 20 has two fans 26 including a fan 26 a driven by amotor 28 for inside air and a fan 26 b driven by a motor 28 for outsideair. The heater 27 includes: a heater core 27 a configured to heat airfor air conditioning; and a heat pipe 27 b in which a refrigerant isevaporated or condensed to transfer heat from a high-temperature part toa low-temperature part.

The first inside air passage 21 a 1, the second inside air passage 21 a2, and the outside air passage 21 b are arranged extending in afront-rear direction. The first inside air passage 21 a 1 and the secondinside air passage 21 a 2 each have an air inlet and an air outletinstalled at the cabin. In addition, the outside air passage 21 b has anair inlet installed outside the cabin and its air outlet side isconnected to each air supply duct 61.

The first inside air passage 21 a 1 and the second inside air passage 21a 2 are adjacent to each other and share a common space in theirpartway. The common space is provided with the filter 25, the fan 26 a,and the heater core 27 a. The fan 26 a is positioned downstream of thefilter 25. The heater core 27 a is positioned downstream of the fan 26a.

The second inside air passage 21 a 2 and the outside air passage 21 bare adjacent to each other. The fan 26 b is arranged in the inside ofthe outside air passage 21 b. In this embodiment, the fan 26 a and thefan 26 b are arranged at substantially the same vehicle-longitudinalposition. In addition, the heat pipe 27 b is arranged in the inside ofthe outside air passage 21 b and the second inside air passage 21 a 2.The heat pipe 27 b is positioned downstream of the heater core 27 a.

Switching doors 24 a and 24 b are provided between the first inside airpassage 21 a 1 and the second inside air passage 21 a 2. The switchingdoor 24 a is positioned upstream of the filter 25. In addition, theswitching door 24 b is positioned downstream of the heater core 27 a andupstream of the heat pipe 27 b. Also, the inside of the outside airpassage 21 b has a switching door 24 c. The switching door 24 c ispositioned upstream of the fan 26 b. The switching doors 24 a, 24 b, and24 c control switching in or between passages. The switching door 24 a,the first inside air passage 21 a 1, the second inside air passage 21 a2, the outside air passage 21 b, and the switching door 24 c provide apassage switching device 24.

The front air conditioning unit 20 causes inside air taken in from thecabin to be pressurized by the fan 26 a and then to flow, via either thefirst inside air passage 21 a 1 or the second inside air passage 21 a 2or both, to the downstream side. At that time, the front airconditioning unit 20, depending on the operation state, causes theinside air to be heated by the heater core 27 a and/or uses the heatpipe 27 b to exchange heat between the inside air and the outside air.After that, the front air conditioning unit 20 releases the inside airinto the cabin.

In addition, the front air conditioning unit 20 causes outside air takenin from the outside to be pressurized by the fan 26 b and then to flow,via the outside air passage 21 b, to the downstream side. At that time,the front air conditioning unit 20, depending on the operation state,uses the heat pipe 27 b to exchange heat between the inside air and theoutside air. After that, the front air conditioning unit 20 supplies theoutside air via each air supply duct 61 to each seat air conditioningunit 30.

<Configuration of Seat Air Conditioning Unit>

With reference to FIG. 5B, the following describes the structure of eachseat air conditioning unit 30. FIG. 5B is a schematic diagram of thestructure of the seat air conditioning unit 30 when viewed from theabove.

As shown in FIG. 5B, each seat air conditioning unit 30 includes: aninside/outside air switching damper 31 for switching an inside air flowand an outside air flow; a fan 36 for causing the inside air to flow;and a heat exchanger 37 for exchanging heat between a refrigerant andthe inside air and between a refrigerant and the outside air. Theinside/outside air switching damper 31 is provided with: two insideair-flowing passages (the first inside air passage 31 a 1 and the secondinside air passage 31 a 2); and two outside air-flowing passages (thefirst outside air passage 31 b 1 and the second outside air passage 31 b2). In addition, the seat air conditioning unit 30 has the heatexchanger 37 including a condenser 37 a, in which a refrigerant iscondensed, and an evaporator 37 b, in which a refrigerant is evaporated.Here, the condenser 37 a and the evaporator 37 b of the seat airconditioning unit 30, together with a compressor (not shown) and anexpansion valve (not shown), are described to constitute a refrigeratingcycle apparatus through which a refrigerant circulates.

The first inside air passage 31 a 1, the second inside air passage 31 a2, the first outside air passage 31 b 1, and the second outside airpassage 31 b 2 are arranged extending in a front-rear direction. Thefirst inside air passage 31 a 1 and the second inside air passage 31 a 2share an air inlet 32 a and each has an air outlet installed at thecabin. In addition, the first outside air passage 31 b 1 and the secondoutside air passage 31 b 2 shares an air inlet 32 b installed outsidethe cabin and their air outlet side is connected to the correspondingexhaust duct 62.

The first inside air passage 31 a 1 and the second inside air passage 31a 2 are formed such that the air inlet 32 a branches into two passages.The first inside air passage 31 a 1 is disposed next to the right outerside of the first outside air passage 31 b 1. The second inside airpassage 31 a 2 is disposed next to the left outer side of the secondoutside air passage 31 b 2. The first outside air passage 31 b 1 and thesecond outside air passage 31 b 2 are adjacent to each other so as topass through, from the air inlet 32 b, substantially the vehiclewidthwise center of the seat air conditioning unit 30.

The first inside air passage 31 a 1 and the first outside air passage 31b 1 share a common space in their partway. The common space is providedwith the condenser 37 a. The second inside air passage 31 a 2 and thesecond outside air passage 31 b 2 share a common space in their partway.The common space is provided with the evaporator 37 b. In thisembodiment, the condenser 37 a and the evaporator 37 b are arranged atsubstantially the same vehicle-longitudinal position.

Switching doors 34 a and 34 b are provided between the first inside airpassage 31 a 1 and the first outside air passage 31 b 1. The switchingdoor 34 a is positioned upstream of the condenser 37 a. In addition, theswitching door 34 b is positioned downstream of the condenser 37 a.

Switching doors 34 c and 34 d are provided between the second inside airpassage 31 a 2 and the second outside air passage 31 b 2. The switchingdoor 34 c is positioned upstream of the evaporator 37 b. In addition,the switching door 34 d is positioned downstream of the evaporator 37 b.The switching doors 34 a, 34 b, 34 c, and 34 d are provided forswitching between passages. The switching doors 34 a and 34 c, the firstinside air passage 31 a 1, the first outside air passage 31 b 1, thesecond outside air passage 31 b 2, and the second inside air passage 31a 2 provide a switching device 34 configured to perform switchingbetween the passages such that during cooling operation, the outside airis guided in a direction toward the condenser 37 a and during heatingoperation, the outside air is guided to a direction toward theevaporator 37 b.

The seat air conditioning unit 30 causes inside air taken in from thecabin to be pressurized by the fan 36 and then to flow, via either thefirst inside air passage 31 a 1 or the second inside air passage 31 a 2,to the downstream side. At that time, in the seat air conditioning unit30, heat is exchanged by the heat exchanger 37 between a refrigerant andthe inside air and between a refrigerant and the outside air. Afterthat, the seat air conditioning unit 30 releases the inside air into thecabin.

Further, the seat air conditioning unit 30 causes outside air taken infrom the outside to flow, via either the first outside air passage 31 b1 or the second outside air passage 31 b 2, to the downstream side. Atthat time, in the seat air conditioning unit 30, heat is exchanged bythe heat exchanger 37 between a refrigerant and the inside air andbetween a refrigerant and the outside air. After that, the seat airconditioning unit 30 sends the outside air, via the correspondingexhaust duct 62, to the corresponding rear blowing unit 40.

Note that in order to circulate inside air between each seat airconditioning unit 30 and the cabin, the seat air conditioning unit 30has the fan 36 on the inside air inlet 32 a side. However, each seat airconditioning unit 30 is provided with no fan (blowing fan) on theoutside air inlet 32 b side.

This is because the air conditioning apparatus 10 has the followingconfiguration which makes it possible to omit a fan (blowing fan) on theoutside air inlet 32 b side.

(a) The air conditioning apparatus 10 is structured such that outsideair is pressurized by the fan 26 b (see FIG. 5A) of the front airconditioning unit 20 and is then delivered from the front airconditioning unit 20 to each seat air conditioning unit 30.

(b) The air conditioning apparatus 10 is structured such that a fan 46driven by a motor 28 (see FIG. 5C) of each rear blowing unit 40 sucksoutside air from each seat air conditioning unit 30 to the rear blowingunit 40.

Such an air conditioning apparatus 10 makes it possible to reduce thenumber of parts by the number of fans (blowing fans) omitted on theoutside air inlet 32 b side. For instance, when the air conditioningapparatus 10 has four seat air conditioning units 30, four outsideair-use fans (blowing fans) can be omitted. In addition, in the airconditioning apparatus 10, the size of each seat air conditioning unit30 can be made compact.

<Configuration of Rear Blowing Unit>

With reference to FIG. 5C, the following describes the structure of eachrear blowing unit 40. FIG. 5C is a schematic diagram of the structure ofthe rear blowing unit 40 when viewed from the above.

As shown in FIG. 5C, each rear blowing unit 40 includes an outside airpassage 41 b through which outside air flows and the fan 46 configuredto cause the outside air to flow. Of the outside air passage 41 b, theair inlet side (starting end side) is connected to the correspondingexhaust duct 62; and the air outlet side (terminal end side) isconnected to a ventilation duct 63. The fan 46 is arranged in the insideof the outside air passage 41 b.

<How Front Air Conditioning Unit Works During Cooling Operation>

With reference to FIG. 6, the following illustrates how the front airconditioning unit 20 works during cooling operation. FIG. 6 is a diagramillustrating how the front air conditioning unit 20 works during coolingoperation.

As shown in FIG. 6, in the front air conditioning unit 20 during coolingoperation, the switching doors 24 a and 24 b are operated to open thefirst inside air passage 21 a 1 and close the second inside air passage21 a 2. In addition, the switching door 24 c is in a state in which theoutside air passage 21 b is open. Further, the heater core 27 a and theheat pipe 27 b are turned OFF.

While kept under such conditions, the front air conditioning unit 20does not actuate the fan 26 a, resulting in a state in which inside aircirculation is stopped. Meanwhile, the front air conditioning unit 20actuates the fan 26 b. Accordingly, outside air is made to flow throughthe outside air passage 21 b to the downstream side and then to passthrough the heat pipe 27 b. At that time, heat is not exchanged betweenthe outside air and the inside air.

<How Front Air Conditioning Unit Works During Heating Operation>

With reference to FIGS. 7A to 7C, the following illustrates how thefront air conditioning unit 20 works when the temperature of a cabinfront section is raised during heating operation. FIG. 7A is a diagramillustrating how the front air conditioning unit 20 works when thetemperature of a cabin front section is raised during heating operation.FIG. 7B is a diagram illustrating how the front air conditioning unit 20works when the outside air temperature is high (at about 0° C.) duringheating operation. FIG. 7C is a diagram illustrating how the front airconditioning unit 20 works when the outside air temperature is lowduring heating operation (when each seat air conditioning unit 30 isdeficient in performance).

(How Front Air Conditioning Unit Works When Temperature of Cabin FrontSection is Raised)

When the temperature of the cabin front section is raised, the front airconditioning unit 20 actuates the heater core 27 a to elevate the cabintemperature around the front air conditioning unit 20. When thetemperature of the cabin front section is raised in such a manner, asshown in FIG. 7A, the switching doors 24 a and 24 b in the front airconditioning unit 20 are operated to open the first inside air passage21 a 1 and close the second inside air passage 21 a 2. In addition, theswitching door 24 c is in a state in which the outside air passage 21 bis open. Further, the heater core 27 a is turned ON and the heat pipe 27b is turned OFF.

While kept under such conditions, the front air conditioning unit 20actuates the fan 26 a to cause inside air to flow through the firstinside air passage 21 a 1 to the downstream side. At that time, finedust is removed by the filter 25. Further, the inside air is then madeto pass through the heater core 27 a for heating. Meanwhile, the frontair conditioning unit 20 actuates the fan 26 b. Accordingly, outside airis made to flow through the outside air passage 21 b to the downstreamside and then to pass through the heat pipe 27 b. At that time, heat isnot exchanged between the outside air and the inside air. After that,the front air conditioning unit 20 delivers the outside air via each airsupply duct 61 to the evaporator 37 b of each seat air conditioning unit30.

(How Front Air Conditioning Unit Works When Outside Air Temperature isHigh)

When the outside air temperature is high (at about 0° C.), the front airconditioning unit 20 only blows air to each seat air conditioning unit30. When the outside air temperature is this high, as shown in FIG. 7B,the switching doors 24 a and 24 b in the front air conditioning unit 20are operated to open the first inside air passage 21 a 1 and close thesecond inside air passage 21 a 2. In addition, the switching door 24 cis in a state in which the outside air passage 21 b is open. Further,the heater core 27 a and the heat pipe 27 b are turned OFF.

While kept under such conditions, the front air conditioning unit 20does not actuate the fan 26 a, resulting in a state in which inside aircirculation is stopped. Meanwhile, the front air conditioning unit 20actuates the fan 26 b to cause outside air to flow through the firstoutside air passage 21 b to the downstream side and to pass through theheat pipe 27 b. At that time, heat is not exchanged between the outsideair and the inside air. After that, the front air conditioning unit 20delivers the outside air via each air supply duct 61 to the evaporator37 b of each seat air conditioning unit 30.

(How Front Air Conditioning Unit Works When Outside Air Temperature isLow)

When the outside air temperature is low, the front air conditioning unit20 actuates the heater core 27 a and the heat pipe 27 b to elevate thecabin temperature and the blowing temperature of the inside air as wellas to increase the blowing temperature of the outside air delivered toeach seat air conditioning unit 30. When the outside air temperature isthis low, as shown in FIG. 7C, the switching doors 24 a and 24 b in thefront air conditioning unit 20 are operated to open the first inside airpassage 21 a 1 and the second inside air passage 21 a 2. In addition,the switching door 24 c is in a state in which the outside air passage21 b is open. Further, the heater core 27 a and the heat pipe 27 b areturned ON. Note that when each seat air conditioning unit 30 cangenerate adequate warm heat, the heater 27 of the front air conditioningunit 20 may be turned OFF.

While kept under such conditions, the front air conditioning unit 20actuates the fan 26 a to cause inside air to flow through the firstinside air passage 21 a 1 and the second inside air passage 21 a 2. Atthat time, fine dust is removed by the filter 25. Further, the insideair is then made to pass through the heater core 27 a for heating.Meanwhile, the front air conditioning unit 20 actuates the fan 26 b tocause outside air to flow through the first outside air passage 21 b tothe downstream side and to pass through the heat pipe 27 b. At thattime, heat is exchanged between the outside air and the inside air bymeans of the heat pipe 27 b. After that, the front air conditioning unit20 delivers the outside air via each air supply duct 61 to theevaporator 37 b of each seat air conditioning unit 30.

Note that the operation illustrated in FIG. 7C is described below. Whenthe outside air temperature is low, the heating capacity of each seatair conditioning unit 30 is likely to be insufficient. In this case, theoperation aims at making it possible for each seat air conditioning unit30 to immediately blow warm air to an occupant.

Specifically, for instance, when the outside air temperature is low,namely when the heating capacity of each seat air conditioning unit 30is likely to be insufficient, electric vehicles without any enginecannot utilize, for heating, heat generated by the engine. In addition,in view of their performance characteristics, refrigerating cycleapparatuses need more time to generate warm air than to generate coldair. Because of this, when the outside air temperature is low, the seatair conditioning unit 30 requires considerable time to generatesufficiently warm air. Thus, when the outside air temperature is low, asshown in FIG. 7C, the heater 27 of the front air conditioning unit 20 inthe air conditioning apparatus 10 is turned ON. This compensates theinsufficient heating capacity of each seat air conditioning unit 30 andmakes it possible for the seat air conditioning unit 30 to immediatelyblow warm air to an occupant.

<How Seat Air Conditioning Unit Works During Cooling Operation>

With reference to FIG. 8, the following illustrates how each seat airconditioning unit 30 works during cooling operation. FIG. 8 is a diagramillustrating how the seat air conditioning unit 30 works during coolingoperation.

As shown in FIG. 8, in each seat air conditioning unit 30 during coolingoperation, the switching doors 34 a and 34 b are operated to close thefirst inside air passage 31 a 1 and open the first outside air passage31 b 1. In addition, the switching doors 34 c and 34 d are operated toclose the second outside air passage 31 b 2 and open the second insideair passage 31 a 2. Further, the condenser 37 a and the evaporator 37 bare turned ON.

While kept under such conditions, the seat air conditioning unit 30actuates the fan 36 to cause inside air to flow through the secondinside air passage 31 a 2 to the downstream side and then to passthrough the evaporator 37 b. At that time, heat is exchanged between theinside air and a refrigerant flowing through the evaporator 37 b. Thiscools the inside air. After that, the seat air conditioning unit 30releases the inside air into the cabin. In addition, each seat airconditioning unit 30 causes outside air delivered from the front airconditioning unit 20 to flow through the first outside air passage 31 b1 and then to pass through the condenser 37 a. At that time, heat isexchanged between the outside air and a refrigerant flowing through thecondenser 37 a. This heats the outside air. After that, the seat airconditioning unit 30 sends the outside air, via the correspondingexhaust duct 62, to the corresponding rear blowing unit 40.

<How Seat Air Conditioning Unit Works During Heating Operation>

With reference to FIG. 9, the following illustrates how each seat airconditioning unit 30 works during heating operation. FIG. 9 is a diagramillustrating how the seat air conditioning unit 30 works during heatingoperation.

As shown in FIG. 9, in each seat air conditioning unit 30 during heatingoperation, the switching doors 34 a and 34 b are operated to open thefirst inside air passage 31 a 1 and close the first outside air passage31 b 1. In addition, the switching doors 34 c and 34 d are operated toopen the second outside air passage 31 b 2 and close the second insideair passage 31 a 2. Further, the condenser 37 a and the evaporator 37 bare turned ON.

While kept under such conditions, each seat air conditioning unit 30actuates the fan 36 to cause inside air to flow through the first insideair passage 31 a 1 to the downstream side and then to pass through thecondenser 37 a. At that time, heat is exchanged between the inside airand a refrigerant flowing through the condenser 37 a. This heats theinside air. After that, the seat air conditioning unit 30 releases theinside air into the cabin. In addition, each seat air conditioning unit30 causes outside air delivered from the front air conditioning unit 20to flow through the second outside air passage 31 b 2 and then to passthrough the evaporator 37 b. At that time, heat is exchanged between theoutside air and a refrigerant flowing through the evaporator 37 b. Thiscools the outside air. After that, the seat air conditioning unit 30sends the outside air, via the corresponding exhaust duct 62, to thecorresponding rear blowing unit 40.

<How Comparative Embodiment is Configured and Works>

Meanwhile, the idea of the air conditioning apparatus 10 according tothe present embodiment can also provide a solution to the problems of anair conditioning apparatus 110 according to the following comparativeembodiment. The air conditioning apparatus 110 according to thecomparative embodiment is structured while ducts are considered to besimplified. With reference to FIGS. 10 to 12, the following describesthe structure and problems of the air conditioning apparatus 110according to the comparative embodiment. FIG. 10 is a schematic diagramof the structure of a seat air conditioning unit 130 of the airconditioning apparatus 110 according to the comparative embodiment whenviewed from a lateral side. FIG. 11 is a diagram illustrating how theseat air conditioning unit 130 according to the comparative embodimentworks during cooling operation. FIG. 12 is a diagram illustrating howthe seat air conditioning unit 130 according to the comparativeembodiment works during heating operation.

When compared to the air conditioning apparatus 10 according to thepresent embodiment, the air conditioning apparatus 110 according to thecomparative embodiment as shown in FIG. 10 has the seat air conditioningunit 130 instead of the seat air conditioning unit 30 (see FIG. 5B).This point is a difference.

The seat air conditioning unit 130 according to the comparativeembodiment is arranged below the seat 104. The seat air conditioningunit 130 according to the comparative embodiment includes: two fans 136(136 a, 136 b) for causing inside air and outside air to flow; and aheat exchanger 137 for exchanging heat between a refrigerant and theinside air and between a refrigerant and the outside air. In addition,the seat air conditioning unit 130 according to the comparativeembodiment has the heat exchanger 137 including a condenser 137 a, inwhich a refrigerant is condensed, and an evaporator 137 b, in which arefrigerant is evaporated.

Also, the seat air conditioning unit 130 according to the comparativeembodiment is provided with: two inside air-flowing passages (the firstinside air passage 131 a 1 and the second inside air passage 131 a 2);and two outside air-flowing passages (the first outside air passage 131b 1 and the second outside air passage 131 b 2). The first outside airpassage 131 b 1 and the second outside air passage 131 b 2 are adjacentto each other in a front-rear direction. The first inside air passage131 a 1 is disposed forwardly of and next to the first outside airpassage 131 b 1. The second inside air passage 131 a 2 is disposedrearwardly of and next to the second outside air passage 131 b 2.

The first inside air passage 131 a 1 is shaped like an inverted Lletter, extending from the bottom to the top, and having an upper endside protruding forwardly below the seat 104. The first inside airpassage 131 a 1 has openings at a lower end portion and a front endportion on the upper end side. The opening of the lower end portionfunctions as an air inlet and the opening of the front end portion onthe upper end side functions as an air outlet. The first inside airpassage 131 a 1 is structured such that inside air is taken in from theopening (air inlet) of the lower end portion and the inside air isdischarged, to the cabin, from the opening (air outlet) of the front endportion on the upper end side.

The second inside air passage 131 a 2 is shaped like a crank, extendingfrom the bottom to the top, having a partway portion curved reward, andfurther having an upper end side protruding forward so as to beconnected to a seatback portion of the seat 104. The second inside airpassage 131 a 2 has openings at a lower end portion and a front endportion on the upper end side. The opening of the lower end portionfunctions as an air inlet and the opening of the front end portion onthe upper end side functions as an air outlet. The second inside airpassage 131 a 2 is structured such that inside air is taken in from theopening (air inlet) of the lower end portion and the inside air isdischarged via the seat 104, to the cabin, from the opening (air outlet)of the front end portion on the upper end side.

The first outside air passage 131 b 1 and the second outside air passage131 b 2 are shaped like an inverted U letter, extending from the bottomto the top, having a partway portion curved reward, and having a leadingend portion bent downward. The first outside air passage 131 b 1 and thesecond outside air passage 131 b 2 have openings at two lower endportions. The opening of the lower end portion (hereinafter, referred toas “one lower end portion”) sandwiched between the first inside airpassage 131 a 1 and the second inside air passage 131 a 2 functions asan air inlet and the opening of the other lower end portion functions asan air outlet. An introduction pipe 160 a is attached to the opening(air inlet) of the one lower end portion. In addition, a discharge pipe160 b is attached to the opening (air outlet) of the other lower endportion. The first outside air passage 131 b 1 and the second outsideair passage 131 b 2 are structured such that outside air is introducedthereinto from the opening (air inlet) of the one lower end portion andthe outside air is discharged outside the cabin from the opening (airoutlet) of the other lower end portion.

The first inside air passage 131 a 1 and the first outside air passage131 b 1 share a common space in their partway. The common spaceincludes, in sequence from the bottom, the condenser 137 a and the fan136 a. The second inside air passage 31 a 2 and the second outside airpassage 31 b 2 share a common space in their partway. The common spaceincludes, in sequence from the bottom, the evaporator 137 b and the fan136 b. In the comparative embodiment, the condenser 137 a and theevaporator 137 b are arranged at substantially the same height position.In addition, the fan 136 a and the fan 136 b are arranged atsubstantially the same height position.

Switching doors 134 a and 134 b are provided between the first insideair passage 131 a 1 and the first outside air passage 131 b 1. Theswitching door 134 a is positioned below the condenser 137 a and the fan136 a. In addition, the switching door 134 b is positioned above thecondenser 137 a and the fan 136 a.

Switching doors 134 c and 134 d are provided between the second insideair passage 131 a 2 and the second outside air passage 131 b 2. Theswitching door 134 c is positioned below the evaporator 137 b and thefan 136 b. In addition, the switching door 134 d is positioned above thecondenser 137 a and the fan 136 a.

As shown in FIG. 11, in the seat air conditioning unit 130 according tothe comparative embodiment during cooling operation, the switching doors134 a and 134 b are operated to close the first inside air passage 131 a1 and open the first outside air passage 131 b 1. In addition, theswitching doors 134 c and 134 d are operated to close the second outsideair passage 131 b 2 and open the second inside air passage 131 a 2.Further, the condenser 137 a and the evaporator 137 b are turned ON.

Under such conditions, the seat air conditioning unit 130 according tothe comparative embodiment actuates the fan 136 a and the fan 136 b. Bydoing so, the seat air conditioning unit 130 according to thecomparative embodiment causes inside air to flow through the secondinside air passage 131 a 2 to the downstream side (in the upperdirection of FIG. 11) and then to pass through the evaporator 137 b. Atthat time, heat is exchanged between the inside air and a refrigerantflowing through the evaporator 137 b. This cools the inside air. Afterthat, the seat air conditioning unit 130 according to the comparativeembodiment releases the inside air into the cabin. In addition, the seatair conditioning unit 130 according to the comparative embodiment causesoutside air to flow through the first outside air passage 131 b 1 to thedownstream side (in the upper direction of FIG. 11) and then to passthrough the condenser 137 a. At that time, heat is exchanged between theoutside air and a refrigerant flowing through the condenser 137 a. Thisheats the outside air. After that, the seat air conditioning unit 130according to the comparative embodiment delivers the outside air to theoutside of the cabin.

As shown in FIG. 12, in the seat air conditioning unit 130 according tothe comparative embodiment during heating operation, the switching doors134 a and 134 b are operated to open the first inside air passage 131 a1 and close the first outside air passage 131 b 1. In addition, theswitching doors 134 c and 134 d are operated to open the second outsideair passage 131 b 2 and close the second inside air passage 131 a 2.Further, the condenser 137 a and the evaporator 137 b are turned ON.

Under such conditions, the seat air conditioning unit 130 according tothe comparative embodiment actuates the fan 136 a and the fan 136 b. Bydoing so, the seat air conditioning unit 130 according to thecomparative embodiment causes inside air to flow through the firstinside air passage 131 a 1 to the downstream side (in the upperdirection of FIG. 11) and then to pass through the condenser 137 a. Atthat time, heat is exchanged between the inside air and a refrigerantflowing through the condenser 137 a. This heats the inside air. Afterthat, the seat air conditioning unit 130 according to the comparativeembodiment releases the inside air into the cabin. In addition, the seatair conditioning unit 130 according to the comparative embodiment causesoutside air to flow through the second outside air passage 131 b 2 tothe downstream side (in the upper direction of FIG. 11) and then to passthrough the evaporator 137 b. At that time, heat is exchanged betweenthe outside air and a refrigerant flowing through the evaporator 137 b.This cools the outside air. After that, the seat air conditioning unit130 according to the comparative embodiment delivers the outside air tothe outside of the cabin.

The air conditioning apparatus 110 according to the comparativeembodiment as so structured has the following problems.

(1) As shown in FIG. 10, the air conditioning apparatus 110 according tothe comparative embodiment has a low degree of design freedom becauseair flow in or out of the seat air conditioning unit 130 is complicated.

(2) As shown in FIG. 10, the air conditioning apparatus 110 according tothe comparative embodiment is difficult to secure space for the fans 136and the switching doors 134 a, 134 b, 134 c, and 134 d because the seatair conditioning unit 130 is configured extending in a verticaldirection. Such an air conditioning apparatus 110 according to thecomparative embodiment has a low degree of design freedom because theheight T130 from a vehicle body floor 101 a is a relatively large valueand is required.

(3) As shown in FIG. 10, the air conditioning apparatus 110 according tothe comparative embodiment needs, as the fans 136 for the heatexchanger, two fans 136 a and 136 b per seat air conditioning unit 130.Such an air conditioning apparatus 110 according to the comparativeembodiment needs a large number of parts, so that the size and cost ofthe seat air conditioning unit 130 increase.

(4) As shown in FIG. 10, the air conditioning apparatus 110 according tothe comparative embodiment needs a plurality of vent holes Ho1 and Ho2on the vehicle body side (e.g., the vehicle body floor 101 a) so as tosecure air passages to the heat exchanger 137. The vent hole Ho1 is aninlet vent hole and the vent hole Ho2 is an outlet vent hole. The airconditioning apparatus 110 according to the comparative embodiment needsto provide two (inlet/outlet) vent holes (Ho1/Ho2) per seat airconditioning unit 130. Due to this, if the number of the seat airconditioning units 130 is 4, for instance, the air conditioningapparatus 110 according to the comparative embodiment needs to provide 8vent holes (Ho1 and Ho2). Because such an air conditioning apparatus 110according to the comparative embodiment is provided with a plurality ofthe vent holes Ho1 and Ho2 on the vehicle body side, rainwater and/orrunning noise may enter the cabin.

(5) Regarding the air conditioning apparatus 110 according to thecomparative embodiment, when the outside air temperature is low, theheat exchanger 137 may not effectively function because the evaporator137 b of the seat air conditioning unit 130 is frosted.

In contrast to the air conditioning apparatus 110 according to thecomparative embodiment, the air conditioning apparatus 10 according tothe present embodiment has the following advantages.

(1) As shown in FIG. 5B, the air conditioning apparatus 10 according tothe present embodiment has an increased degree of design freedom becauseair flow in or out of the seat air conditioning unit 30 is simplified.

(2) As shown in FIG. 5B, the air conditioning apparatus 10 according tothe present embodiment is easy to secure space for the fan 36 and theswitching doors 34 a, 34 b, 34 c, and 34 d because the seat airconditioning unit 30 is configured extending in a front-rear direction.Such an air conditioning apparatus 10 according to the presentembodiment differs from the air conditioning apparatus 110 according tothe comparative embodiment. The height from the vehicle body floor 101 acan be lowered, so that the degree of design freedom can be enhanced.

(3) As shown in FIG. 5B, the air conditioning apparatus 10 according tothe present embodiment is provided, per seat air conditioning unit 30,with just one fan 36 for the inside air heat exchanger, so that a fan(blowing fan) for the outside air heat exchanger can be omitted. In suchan air conditioning apparatus 10 according to the present embodiment,the number of parts can be reduced by the number of the fans (blowingfans) for the outside air heat exchanger, so that the size and cost ofthe seat air conditioning unit 30 can improve.

(4) As shown in FIG. 5B, the air conditioning apparatus 10 according tothe present embodiment differs from the air conditioning apparatus 110according to the comparative embodiment and does not have to be providedwith a plurality of vent holes on the vehicle body side (e.g., thevehicle body floor) so as to secure air passages to the heat exchanger37. Such an air conditioning apparatus 10 according to the presentembodiment differs from the air conditioning apparatus 110 according tothe comparative embodiment, such that rainwater and/or running noise canbe prevented from entering the cabin.

(5) Regarding the air conditioning apparatus 10 according to the presentembodiment, like the air conditioning apparatus 110 according to thecomparative embodiment, when the outside air temperature is low, theevaporator 37 b of each seat air conditioning unit 30 may be frosted.However, as shown in FIG. 7C, the air conditioning apparatus 10according to the present embodiment operates, when the outside airtemperature is low, the front air conditioning unit 20 to open the firstinside air passage 21 a 1 and the second inside air passage 21 a 2 ofthe front air conditioning unit 20 such that the inside air is made topass through the heater 27. This makes it possible to increase thevolume of heated inside air supplied to the cabin by the airconditioning apparatus 10 according to the present embodiment. In suchan air conditioning apparatus 10 according to the present embodiment,when the outside air temperature is low, the heater 27 of the front airconditioning unit 20 can help defrost the evaporator 37 b of the seatair conditioning unit 30. Because of this, the air conditioningapparatus 10 according to the present embodiment differs from the airconditioning apparatus 110 according to the comparative embodiment andcan prevent the heat exchanger 37, even when the outside air temperatureis low, from malfunctioning due to the frosted evaporator 37 b of theseat air conditioning unit 30.

<Main Features of Air Conditioning System According to PresentEmbodiment>

(1) As shown in FIG. 2, the air conditioning apparatus 10 (vehicle airconditioning apparatus) according to the present embodiment includes aplurality of seat air conditioning units 30 for cooling or heating whichis selectively performed per corresponding seat 104 among a plurality ofseats 104 installed in the cabin 103. In addition, the air conditioningapparatus 10 is provided with a plurality of exhaust ducts 62FR, 62FL,62RR, and 62RL for discharging, outside the cabin 103, part of air usedin the seat air conditioning units 30. At least part of the plurality ofexhaust ducts 62FR, 62FL, 62RR, and 62RL is merged.

In such an air conditioning apparatus 10 according to the presentembodiment, the ducts 60 (in particular, exhaust ducts 62) can besimplified. In addition, the air conditioning apparatus 10 can gatherand discharge through exhaust ducts 62, part of air (outside air),together with heat, used in the seat air conditioning units 30 (that is,heat of each seat air conditioning unit 30 can be drained together).Also, in the air conditioning apparatus 10, the size of each seat airconditioning unit 30 can be made compact. Thus, in the air conditioningapparatus 10, the degree of design freedom can be enhanced.

(2) As shown in FIG. 2, the air conditioning apparatus 10 (vehicle airconditioning apparatus) according to the present embodiment is providedwith a plurality of air supply ducts 61FR, 61FL, 61RR, and 61RL forsupplying outside air to the seat air conditioning units 30. At leastpart of the plurality of air supply ducts 61FR, 61FL, 61RR, and 61RL ismerged.

In such an air conditioning apparatus 10 according to the presentembodiment, the ducts 60 (in particular, air supply ducts 61) can besimplified. In addition, the air conditioning apparatus 10 can use theair supply ducts 61 to supply outside air for heat exhaust to each seatair conditioning unit 30 (i.e., air is together supplied to each seatair conditioning unit 30). In such an air conditioning apparatus 10, thefront air conditioning unit 20, the seat air conditioning units 30, andthe rear blowing units 40 can share a fan for outside air heatexchanger. As a result, in the air conditioning apparatus 10, the fan(blowing fan) for the outside air heat exchanger of each seat airconditioning unit 30 can be omitted (see FIG. 5B). For instance, whenthe air conditioning apparatus 10 has four seat air conditioning units30, four fans (blowing fans) for outside air heat exchanger can beomitted. Due to this, in the air conditioning apparatus 10, the size andcost of each seat air conditioning unit 30 can be improved. Also, in theair conditioning apparatus 10, vent holes between each heat exchangerand the outside of the cabin may be unified, so that the number ofvehicle vent holes can be reduced. Thus, in the air conditioningapparatus 10, a risk of water infiltration and/or noise can bedecreased. Further, in the air conditioning apparatus 10, thesurrounding members can be simplified.

(3) As shown in FIG. 5B, in the air conditioning apparatus 10 (vehicleair conditioning apparatus) according to the present embodiment, it ispreferable that each seat air conditioning unit 30 has the followingconfiguration. Specifically, the air conditioning apparatus 10 has thecondenser 37 a for condensing a refrigerant and the evaporator 37 b forevaporating a refrigerant. In addition, the air conditioning apparatus10 has passages for flowing outside air and inside air (the first insideair passage 31 a 1, the second inside air passage 31 a 2, the firstoutside air passage 31 b 1, and the second outside air passage 31 b 2).Further, the air conditioning apparatus 10 has a passage switchingdevice 34 (switching doors 34 a, 34 b, 34 c, and 34 d) for switchingbetween passages such that during cooling operation, outside air isguided in a direction toward the condenser 37 a and during heatingoperation, outside air is guided in a direction toward the evaporator 37b.

In such an air conditioning apparatus 10 according to the presentembodiment, even when the outside air temperature is low and thecapacity of each seat air conditioning unit 30 is insufficient, theevaporator 37 b of each seat air conditioning unit 30 is defrosted, sothat heat absorption efficiency of the heat exchanger 37 of each seatair conditioning unit 30 can be increased.

(4) As shown in FIG. 5B, in the air conditioning apparatus 10 (vehicleair conditioning apparatus) according to the present embodiment, it ispreferable that each seat air conditioning unit 30 has the followingconfiguration. Specifically, the air conditioning apparatus 10 has thefirst outside air passage 31 b 1 through which outside air flows intothe condenser 37 a and the second outside air passage 31 b 2 throughwhich outside air flows into the evaporator 37 b. In addition, the airconditioning apparatus 10 has the first inside air passage 31 a 1through which inside air flows into the condenser 37 a and the secondinside air passage 31 a 2 through which inside air flows into theevaporator 37 b. Here, in the air conditioning apparatus 10, the airinlet of the first outside air passage 31 b 1 and the air inlet of thesecond outside air passage 31 b 2 are merged. In addition, in the airconditioning apparatus 10, the air outlet of the first outside airpassage 31 b 1 and the air outlet of the second outside air passage 31 b2 are merged. Further, in the air conditioning apparatus 10, the airinlet of the first inside air passage 31 a 1 and the air inlet of thesecond inside air passage 31 a 2 are merged.

In such an air conditioning apparatus 10 according to the presentembodiment, the outside air-use air inlets are merged, the outsideair-use air outlets are merged, and the inside air-use air inlets aremerged, so that the size of each seat air conditioning unit 30 can bemade compact. Thus, in the air conditioning apparatus 10, the degree ofdesign freedom can be enhanced.

(5) As shown in FIGS. 8 and 9, it is preferable that the airconditioning apparatus 10 (vehicle air conditioning apparatus) accordingto the present embodiment has the following configuration. Specifically,in the air conditioning apparatus 10, the first outside air passage 31 b1 and the first inside air passage 31 a 1 share a common space aroundthe condenser 37 a. In addition, in the air conditioning apparatus 10,the second outside air passage 31 b 2 and the second inside air passage31 a 2 share a common space around the evaporator 37 b. As shown in FIG.8, the passage switching device 34 (switching doors 34 a, 34 b, 34 c,and 34 d) can be used to switch between passages such that duringcooling operation, outside air passes through the first outside airpassage 31 b 1 and inside air passes through the second inside airpassage 31 a 2. As shown in FIG. 9, the passage switching device 34(switching doors 34 a, 34 b, 34 c, and 34 d) can be used to switchbetween passages such that during heating operation, outside air passesthrough the second outside air passage 31 b 2 and inside air passesthrough the first inside air passage 31 a 1.

Such a seat air conditioning unit 30 of the air conditioning apparatus10 according to the present embodiment has a simple structure and canthen implement outside air heat exchange and inside air heat exchange.Thus, in the air conditioning apparatus 10, the degree of design freedomcan be enhanced.

As described above, the air conditioning apparatus 10 according to thepresent embodiment makes it possible to reduce the number of blowingfans (see FIG. 5B).

The present invention is not limited to the above embodiment(s) and canbe variously modified and/or altered without departing from the spiritof the present invention.

For instance, the number of the seat air conditioning units 30 is notlimited to four and may be two or more.

In addition, for instance, in the above embodiment(s), exemplified isthe case where the seats 104 are provided at two rows: the front row andthe rear low. However, the number of rows for the seats 104 may be threeor more. In this case, the linear pipe arranged at substantially themiddle branches into the air supply ducts 61 such that the number ofbranches is increased by the number of the seat air conditioning units30 installed at the respective seats 104 at or after the third row andeach air supply duct 61 is connected to the corresponding seat airconditioning unit 30. In addition, the seat air conditioning units 30installed at the respective seats 104 at or after the third row each usesubstantially the same air supply duct 61 and exhaust duct 62 as of theseat air conditioning units 30 at the first or second row to beconnected to the front air conditioning unit 20 and the correspondingrear blowing unit 40, respectively.

REFERENCE SIGNS LIST

10 Air conditioning apparatus (vehicle air conditioning apparatus)

20 Front air conditioning unit

21 Inside/outside air switching damper

21 a 1 First inside air passage

21 a 2 Second inside air passage

21 b Outside air passage

24 a, 24 b, 24 c (24) Switching door (switching device)

25 Filter

26 (26 a, 26 b) Fan

27 Heater

27 a Heater core

27 b Heat pipe

30 (30FR, 30FL, 30RR, 30RL) Seat air conditioning unit

31 Inside/outside air switching damper

31 a 1 First inside air passage (flow path)

31 a 2 Second inside air passage (flow path)

31 b 1 First outside air passage (flow path)

31 b 2 Second outside air passage (flow path)

32 a, 32 b Air inlet

34 a, 34 b, 34 c, 34 d (34) Switching door (passage switching device)

36 Fan

37 Heat exchanger

37 a Condenser

37 b Evaporator

40 (40R, 40L) Rear blowing unit

41 b Outside air passage

46 Fan

50 a Introduction port

50 b Vent hole

60 Duct

61 (61FR, 61FL, 61RR, 61RL) Air supply duct

62 (62FR, 62FL, 62RR, 62RL) Exhaust duct

63 (63R, 63L) Ventilation duct

100 Vehicle

102 Front section

103 Cabin

104 Seat

1. A vehicle air conditioning apparatus comprising: a plurality of seatair conditioning units configured to selectively perform cooling orheating for corresponding seats installed in a cabin, respectively; anda plurality of exhaust ducts for discharging, outside the cabin, part ofair used in the plurality of seat air conditioning units, wherein atleast part of the plurality of exhaust ducts is merged.
 2. The vehicleair conditioning apparatus according to claim 1, further comprising aplurality of air supply ducts for supplying outside air to the pluralityof seat air conditioning units, wherein at least part of the pluralityof air supply ducts is merged.
 3. The vehicle air conditioning apparatusaccording to claim 1, wherein each seat air conditioning unit comprises:a condenser for condensing a refrigerant; an evaporator for evaporatinga refrigerant; passages through which outside air or inside air flows;and a passage switching device configured to perform switching betweenthe passages such that during cooling operation, the outside air isguided in a direction toward the condenser and during heating operation,the outside air is guided to a direction toward the evaporator.
 4. Thevehicle air conditioning apparatus according to claim 3, wherein eachseat air conditioning unit further comprises: a first outside airpassage through which the outside air flows into the condenser; a secondoutside air passage through which the outside air flows into theevaporator; a first inside air passage through which the inside airflows into the condenser; and a second inside air passage through whichthe inside air flows into the evaporator, wherein an air inlet of thefirst outside air passage and an air inlet of the second outside airpassage are merged; an air outlet of the first outside air passage andan air outlet of the second outside air passage are merged; and an airinlet of the first inside air passage and an air inlet of the secondinside air passage are merged.
 5. The vehicle air conditioning apparatusaccording to claim 4, wherein the first outside air passage and thefirst inside air passage share a common space around the condenser; thesecond outside air passage and the second inside air passage share acommon space around the evaporator; and the passage switching device isconfigured to switch between the passages such that during coolingoperation, the outside air passes through the first outside air passageand the inside air passes through the second inside air passage andduring heating operation, the outside air passes through the secondoutside air passage and the inside air passes through the first insideair passage.
 6. The vehicle air conditioning apparatus according toclaim 2, wherein each seat air conditioning unit comprises: a condenserfor condensing a refrigerant; an evaporator for evaporating arefrigerant; passages through which outside air or inside air flows; anda passage switching device configured to perform switching between thepassages such that during cooling operation, the outside air is guidedin a direction toward the condenser and during heating operation, theoutside air is guided to a direction toward the evaporator.
 7. Thevehicle air conditioning apparatus according to claim 6, wherein eachseat air conditioning unit further comprises: a first outside airpassage through which the outside air flows into the condenser; a secondoutside air passage through which the outside air flows into theevaporator; a first inside air passage through which the inside airflows into the condenser; and a second inside air passage through whichthe inside air flows into the evaporator, wherein an air inlet of thefirst outside air passage and an air inlet of the second outside airpassage are merged; an air outlet of the first outside air passage andan air outlet of the second outside air passage are merged; and an airinlet of the first inside air passage and an air inlet of the secondinside air passage are merged.
 8. The vehicle air conditioning apparatusaccording to claim 7, wherein the first outside air passage and thefirst inside air passage share a common space around the condenser; thesecond outside air passage and the second inside air passage share acommon space around the evaporator; and the passage switching device isconfigured to switch between the passages such that during coolingoperation, the outside air passes through the first outside air passageand the inside air passes through the second inside air passage andduring heating operation, the outside air passes through the secondoutside air passage and the inside air passes through the first insideair passage.